实验室常用的层析法有几种？

阅读理解。

       Mabel is a cashier (收银员) in a big shop in New York. People can buy medicine, watches, sweets, and many other things. They pay Mabel for the things they buy.

      At the shop people can also buy lottery tickets ( * * ) . They pay one dollar for a lottery ticket. There are pictures on the ticket. Some pictures are winning pictures, and some pictures are losing pictures. Most people win nothing. Some people win two dollars. A few lucky people win thousands of dollars.

      One day Mabel was working at the shop. She sold three lottery tickets to a woman. The woman

looked at the pictures on the tickets. Then she threw the tickets on the counter (柜台) and walked away.  

“These are losing tickets,” she thought.

      Mabel picked up the tickets and looked at them. She was surprised. Then she was excited (兴奋的). One ticket was a winning ticket!

     “Excuse me!” Mabel called to the woman. “You won $ 50,000!”

         The woman came back to the counter. She took the winning ticket and looked at it “You're right,”

she said. “I won $50,000.”

        The woman walked away slowly, looking at the ticket again and again. Then she turned around.

“Thank you! Thank you very much!” she said to Mabel.

        Why did Mabel give the woman the ticket? Why didn't she keep the ticket? Didn't she want the

$50,000?

      “Of course I wanted the money,” Mabel said. “But it was her ticket. It wasn't my ticket.”

      "Well, I'm sorry that you aren't rich,” her mother said. “But I'm happy that you're honest (诚实)."

1. Mabel _______ at the big shop.      

A. receives and pays out money

B. puts things on the shelve

C. helps people choose things

D. carries things for old people

2. One lottery ticket costs _______ .

A. nothing      

B. three dollars    

C. two dollars    

D. one dollar

3. The woman was lucky because _______ .   

A. all her three tickets were winning tickets

B. all her three tickets were losing tickets

C. Mabel found the winning ticket and gave it back to her

D. she found the winning ticket herself

4. Mabel didn't keep the winning ticket because _______ .   

A. she won $50,000 , too

B. her mother told her not to do so 

C. she didn't want to have anything that was not hers

D. her mother was very rich

5. Which sentence is true?

A. Mabel is so foolish.

B. Mabel's mother was angry.

C. The women got the money at last.

D. The woman was sad .

早期妊娠时，羊膜囊被下列哪一结构围绕

A．羊膜

B．绒毛膜

C．蜕膜

D．胎盘

E．卵黄囊

关于前列腺肥大哪种说法是错误的()

A．与雄激素和雌激素平衡失调有关

B．增大的前列腺呈结节状，切面筛孔状

C．前列腺的腺体、平滑肌和纤维组织不同程度增生

D．腺腔内可见淀粉样小体

E．是一种肿瘤性疾病

某项目建设期两年，第1年贷款100万元，第2年贷款200万元，贷款分年度均衡发放，年利率10%，则建设期贷款利息为( )万元。

A．30

B．15

C．25.5

D．25

人类进入近代以来，各国的孤立状态逐渐被打破，各国之间的经济贸易来往不断扩大、日益频繁。

材料一：在（公元）1500年以前，阿拉伯和意大利商人在亚欧大陆上从一个地区运货到另一个地区，而货物主要是奢侈品、香料、丝绸、宝石及香水。但是到18世纪后期新世界的种植场生产的大量砂糖、咖啡及棉花等大部分运往欧洲出售；西班牙人也向新世界引进欧洲各种水果，如橄榄以及葡萄。美洲的特产也被流向世界各地，如玉米、马铃薯、西红柿、番薯、花生、各种豆类及南瓜、可可等。

——吴于廑、齐世荣主编《世界史·近代史》

材料二：英国诺丁汉大学教授郑永年指出：所谓的一个国家外部的崛起，实际上是它内部力量的一个外延，在一个国家内部，自己的国家制度还没有健全的情况下，就很难成为一个大国，即使成为一个大国，也是不可能持续的。……环顾当时的世界，法国正处于君主专制的鼎盛时期；……大清王朝268年的江山才刚刚坐了44年。但是英国，这个地处边缘的小国，却在历史性的转变中抢了先机，已经率先到达了现代文明的入口处，即将一步步稳健地走向世界的中心。在下两个世纪里，它将傲视全球。

——《大国崛起》之“走向现代（英国）”

材料三：火车、轮船、电报等新式交通工具和电讯器材的出现，把世界各地的生产、流通和消费紧紧联结在一起。1869年苏伊士运河通航，使欧洲到印度的航路缩短了4000英里。1914年竣工的巴拿马运河则使旧金山到利物浦的航程近了5666英里。轮船的不断更新使航速大大提高，欧美航程从42天缩短为5天，从伦敦到加尔各答也由3个月减为18天。此外跨洲铁路的修建，加强了洲际联系。有线电报、电话和无线电报的普及，使世界通讯网络得以形成。

——斯塔夫里阿诺斯《全球通史》

材料四：

根据材料一说明18世纪后期世界发生了哪些变化？简析其原因。